Why would the destruction of TWA 800 require "live ordinance" to create a massive failure of the structural integrity of the aircraft?
We all know that the central fuel tank exploded, but we also know that aviation fuel is not explosive unless it has the proper fuel-air mixture. Something atomized the fuel in the aircraft's tank, mixed it with the air, and created the correct mixture.
That is what a carburetor in a car does. Without the proper fuel-air mixture, your engine simply does not go bang.
You have placed logical blinders upon yourself, that may or may not be supported.